It'd be worth giving Glass Key in the Lower Haight a call. He has boxes of various cameras in various states of repair and such-
https://www.facebook.com/pages/Glass...19199231470385

Have you tried covers from other cameras? I've had luck with a Pentax battery cover on a Nikon. Not sure what the Rollei 35 LED cover looks like, but in the manual it has a rather typical look to it.